1. Field of the Invention
The present invention relates to a testing agent for neutrophil function.
2. Description of the Prior Art
Leucocytes for preventing infections in animals are classified into polymorphonuclear leucocytes and mononuclear leucocytes according to their nuclear morphology. Polymorphonuclear leucocytes are further classified into neutrophils, eosinophils and basophils in accordance with the staining of granules. Neutrophils account for about half of the total number of leucocytes.
Neutrophils, as in the case of macrophages, intake foreign substances such as bacteria, i.e., perform ingestion and kill or digest these substances. When these functions of neutrophils are impaired, an organism is easily infected by various bacteria. Typically, these functions are impaired in the disease such as chronic granulomatous disease, Chediak Higashi syndrome and the like. Therefore, when the neutrophil function is tested, the resistance of a subject to an infectious bacterium can be determined and disease caused thereby can be predicted. Further, recent studies in this field show that nutrophils function in the specific immune response.
Conventional neutrophil function testing methods include the following: a testing method wherein heparin-added venous blood is passed through a nylon fiber and afterwards the decreased number of neutrophils is counted; a testing method wherein a bacterium and opsonin are directly added to neutrophils to test the phagocytosis and killing functions; a testing method wherein the metabolism activity upon phagocytosis is determined by utilizing reduction of nitroblue tetrazolium as an index; and a testing method wherein the amount of hydrogen peroxide produced upon phagocytosis is measured. However, only some of various functions of neutrophils can be examined even by these conventional methods which involve complex procedures and require expensive reagents.